The results of this study will demonstrate whether Gly16Arg or Gln27Glu genotypes and/or β2AR haplotypes are associated with the response to albuterol in patients who experience acute episodes of asthma and whether genotype pattern varies between different clinical phenotypes. They will also provide insights into whether such polymorphisms determine the severity of the episodes as measured by initial pulmonary function and symptoms. In this investigation, both positive and negative results would be extremely important. Positive findings would suggest that we can begin to make sense out of therapeutic responsiveness at a very basic level. They also suggest that we need to begin to search for alternative treatments for a significant segment of the asthmatic population when they become acutely ill. Equally important it means that our efforts on asthma control need no longer be diffusely applied, but now can be focused on prophylaxis in affected individuals. Negative findings will conclusively demonstrate that genetically determined changes in B2AR cannot readily be translated into clinical responses and that we need to look for other factors that determine severity and resource utilization in the beta2 unresponsive population.